Porch Preparation

Despite the warm winter we’ve been having, Ontario is still a place that often gets plenty of snow. And you have to account for snow load on a house in all kinds of ways. With porches or any lower roof, you have to plan for the sudden shear forces from snow falling from the a higher main roof. A lot of, let’s call them ‘country porches’, the kind of self-built, not-really-to-code constructions you see all over rural Ontario, look cute, but often aren’t built with shear forces in mind.

There are basically two ways of building a porch that is strong enough to resist these shear forces. One is to have the porch as a structurally independent construction, with a two lines of posts, one on the outside, as all porches will have, and another on the inside next to the external wall of the house. The other is to have the porch connected strongly to the structural elements of the house walls. In our case, because the house has solid Cross-Laminated Timber (CLT) walls, it is relatively easy to do the latter. This means that connections and the main beams for the porch roof have to be installed now, while we are wrapping the house in insulation.

Our porch components, like the main house assembly and the roof rafters, were also designed by Tomaz Stich and prefabricated by Merk in Germany, along with the rest of the house structure. The connections to the house were modelled after another CLT construction that Tomaz is also involved in, in Calgary, and manufactured by Chris of New Leaf Custom Homes, our builder. The engineer we had look at the designers insisted on extra steel brackets, so the connections will be somewhat over-engineered, but they will definitely by strong enough to resist any sudden dump of snow, and probably even being hit by a meteorite from space…

Of course, the porch itself will have to wait until the rest of the house is finished and we are able to pour its separate foundation. Winter seems to be coming to an end, so maybe that won’t be so long after all!

Porch Design (axometric)

The main beam is the same length as the house

Positioning a heavy, 36′ beam isn’t easy

Dan holds up his end…

Holding screws go in

The blocks have to be as deep as the insulation (over 11″), and fitted with steel braces top and bottom